Food Science Commons^™

Native Cellular Architecture Of Treponema Denticola Revealed By Cryo-Electron Tomography, Jacques Izard, Chyong-Ere Hsieh, Ronald J. Limberger, Carmen A. Mannella, Michael Marko

Department of Food Science and Technology: Faculty Publications

Using cryo-electron tomography, we are developing a refined description of native cellular structures in the pathogenic spirochete Treponema denticola. Tightly organized bundles of periplasmic flagella were readily observed in intact plunge-frozen cells. The periplasmic space was measured in both wild-type and aflagellate strains, and found to widen by less than the diameter of flagella when the latter are present. This suggests that a structural change occurs in the peptidoglycan layer to accommodate the presence of the flagella. In dividing cells, the flagellar filaments were found to bridge the cytoplasmic cylinder constriction site. Cytoplasmic filaments, adjacent to the inner membrane, …

Processing Of The Phalloidin Proprotein By Prolyl Oligopeptidase From The Mushroom Conocybe Albipes, Hong Luo, Heather E. Hallen-Adams, Jonathan D. Walton

Department of Food Science and Technology: Faculty Publications

The peptide toxins of poisonous Amanita mushrooms are bicyclic octapeptides (amatoxins) or heptapeptides (phallotoxins). In Amanita bisporigera, α-amanitin and phallacidin are synthesized as 35- and 34-amino acid proproteins, respectively, in which the amino acid sequences found in the mature toxins are flanked by conserved amino acid sequences. The presence of invariant Pro residues immediately upstream of the toxin regions and as the last predicted amino acid in the toxin regions themselves suggests that a Pro-specific peptidase is responsible for the initial post-translational processing of the Amanita toxin proproteins. We purified an enzyme from the phalloidin-producing mushroom Conocybe albipes that …

Genomic Regions Conserved In Lineage Ii Escherichia Coli O157:H7 Strains, Marina Steele, Kim Ziebell, Yongxiang Zhang, Andrew K. Benson, Roger Johnson, Chad Laing, Eduardo Taboada, Victor Gannon

Department of Food Science and Technology: Faculty Publications

Populations of the food- and waterborne pathogen Escherichia coli O157:H7 are comprised of two major lineages. Recent studies have shown that specific genotypes within these lineages differ substantially in the frequencies with which they are associated with human clinical disease. While the nucleotide sequences of the genomes of lineage I strains E. coli O157 Sakai and EDL9333 have been determined, much less is known about the genomes of lineage II strains. In this study, suppression subtractive hybridization (SSH) was used to identify genomic features that define lineage II populations. Three SSH experiments were performed, yielding 1,085 genomic fragments consisting of …

Genomic Instability In Regions Adjacent To A Highly Conserved Pch Prophage In Escherichia Coli O157:H7 Generates Diversity In Expression Patterns Of The Lee Pathogenicity Island, Zhijie Yang, Jaehyoung Kim, Chaomei Zhang, Min Zhang, Joeseph Nietfeldt, Carolyn M. Southward, Michael G. Surette, Stephen D. Kachman, Andrew K. Benson

Department of Food Science and Technology: Faculty Publications

The LEE pathogenicity island has been acquired on multiple occasions within the different lineages of

enteropathogenic and enterohemorrhagic Escherichia coli. In each lineage, LEE expression is regulated by complex networks of pathways, including core pathways shared by all lineages and lineage-specific pathways. Within the O157:H7 lineage of enterohemorrhagic E. coli, strain-to-strain variation in LEE expression has been observed, implying that expression patterns can diversify even within highly related subpopulations. Using comparative genomics of E. coli O157:H7 subpopulations, we have identified one source of strain-level variation affecting LEE expression. The variation occurs in prophage-dense regions of the genome that …

Pyramidobacter Piscolens Gen. Nov., Sp. Nov., A Member Of The Phylum ‘Synergistetes’ Isolated From The Human Oral Cavity, Julia Downes, Sonia R. Vartoukian, Floyd E. Dewhirst, Jacques Izard, Tsute Chen, Wen-Han Yu, Iain C. Sutcliffe, William G. Wade

Department of Food Science and Technology: Faculty Publications

Four strains of anaerobic, gram-negative bacilli isolated from the human oral cavity were subjected to a comprehensive range of phenotypic and genotypic tests and were found to comprise a homogeneous group distinct from any species with validly published names. 16S rRNA and 23S rRNA gene sequence analyses and DNA–DNA reassociation data revealed that the strains constituted a novel group within the phylum ‘Synergistetes’ and were most closely related to Jonquetella anthropi. Two libraries of randomly cloned DNA were prepared from strain W5455T and were sequenced to provide a genome survey as a resource for metagenomic studies. A new genus …

Cryo-Electron Tomography Elucidates The Molecular Architecture Of Treponema Pallidum, The Syphilis Spirochete, Jacques Izard, Christian Renken, Chyong-Ere Hsieh, Daniel C. Desrosiers, Star Dunham-Ems, Carson La Vake, Linda L. Gebhardt, Ronald J. Limberger, David L. Cox, Michael Marko, Justin D. Radolf

Department of Food Science and Technology: Faculty Publications

Cryo-electron tomography (CET) was used to examine the native cellular organization of Treponema pallidum, the syphilis spirochete. T. pallidum cells appeared to form flat waves, did not contain an outer coat and, except for bulges over the basal bodies and widening in the vicinity of flagellar filaments, displayed a uniform periplasmic space. Although the outer membrane (OM) generally was smooth in contour, OM extrusions and blebs frequently were observed, highlighting the structure’s fluidity and lack of attachment to underlying periplasmic constituents. Cytoplasmic filaments converged from their attachment points opposite the basal bodies to form arrays that ran roughly …

Triacylglyceride Metabolism By Fusarium Graminearum During Colonization And Sexual Development On Wheat, John C. Guenther, Heather E. Hallen-Adams, Heike Bücking, Yair Shachar-Hill, Frances Trail

Department of Food Science and Technology: Faculty Publications

Fusarium graminearum, a devastating pathogen of small grains, overwinters on crop residues and produces ephemeral perithecia. Accumulation of lipids in overwintering hyphae would provide reserves for overwinter survival and perithecium development. Fatty acid composition of cultures during perithecium development indicated a drop in neutral lipid levels during development but little change in fatty acid composition across stages. Microscopic examination of cultures early in sexual development revealed hyphal cells engorged with lipid bodies. In comparison, vegetative hyphae contained few lipid bodies. Microarray analysis was performed on wheat stems at stages of colonization through perithecium development. Gene expression analysis during stages of …

Diet-Induced Metabolic Improvements In A Hamster Model Of Hypercholesterolemia Are Strongly Linked To Alterations Of The Gut Microbiota, Inés Martínez, Chaomei Zhang, Ryan Legge, Andrew K. Benson, Timothy P. Carr, Etsuko N. Moriyama, Jens Walter

Department of Food Science and Technology: Faculty Publications

The mammalian gastrointestinal microbiota exerts a strong influence on host lipid and cholesterol metabolism. In this study, we have characterized the interplay among diet, gut microbial ecology, and cholesterol metabolism in a hamster model of hypercholesterolemia. Previous work in this model had shown that grain sorghum lipid extract (GSL) included in the diet significantly improved the high-density lipoprotein (HDL)/ non-HDL cholesterol equilibrium (T. P. Carr, C. L. Weller, V. L. Schlegel, S. L. Cuppett, D. M. Guderian, Jr., and K. R. Johnson, J. Nutr. 135:2236-2240, 2005). Molecular analysis of the hamsters’ fecal bacterial populations by pyrosequencing of 16S rRNA tags, …

Clinical Relevance Of Sensitization To Lupine In Peanut-Sensitized Adults, K. A. B. M. Peeters, Stef J. Koppelman, A. H. Penninks, A. Lebens, C. A. F. M. Bruijnzeel-Koomen, S. L. Hefle, S. L. Taylor, E. Van Hoffen, A. C. Knulst

Department of Food Science and Technology: Faculty Publications

Background: The use of lupine in food has been increasing during the last decade and allergic reactions to lupine have been reported, especially in peanut-allergic patients. The frequency and the degree of cross-reactivity to other legumes are not known. The aim of the study was to investigate the frequency of sensitization to lupine, and in addition to pea and soy, and its clinical relevance, in peanutsensitized patients. Furthermore, to determine the eliciting dose (ED) for lupine using double-blind placebo-controlled food challenges (DBPCFC).

Methods: Thirty-nine unselected peanut-sensitized patients were evaluated by skin prick tests (SPT) and ImmunoCAP to lupine, pea, and …

Characterization Of Dna Sequences That Confer Complement Resistance In Leishmania Chagasi, Rebecca R. Dahlin-Laborde, Eric J. Scolaro, Nathan M. Romine, Amanda Ramer-Tait, Soi Meng Lei, Jeffrey K. Beetham

Department of Food Science and Technology: Faculty Publications

Serial passage of axenically cultured Leishmania chagasi promastigotes results in a progressive diminution in resistance to complement-mediated lysis (CML), whereas high CML resistance is seen in infectious metacyclic promastigotes from the sandfly vector as well as metacyclic-like promastigotes within low-passage cultures at stationary growth phase. As we previously reported, in a screen seeking to identify novel genes involved in CML resistance: (1) a genomic cosmid library derived from DNA of CML-resistant L. chagasi promastigotes was transfected into highpassage (constitutively CML-sensitive) L. chagasi promastigotes; (2) transformants were screened for acquisition of CML-resistance; (3) multiple cosmid-transfectants exhibited partial CML resistance; and (4) …

Disseminated Leishmania Infantum Infection In Two Sibling Foxhounds Due To Possible Vertical Transmission, Katherine N. Gibson-Corley, Jesse M. Hostetter, Shannon J. Hostetter, Kathleen Mullin, Amanda Ramer-Tait, Paola M. Boggiatto, Christine A. Petersen

Department of Food Science and Technology: Faculty Publications

Two sibling foxhounds born to a Leishmania seropositive bitch were presented after testing seropositive for Leishmania. Leishmania infantum infection was detected via histopathology, culture, and quantitative polymerase chain reaction (q-PCR). This is the first report of natural infection with Leishmania infantum with the possibility for vertical transmission in North America.

Infection disséminée à Leishmania infantum chez deux chiots Fox hound d’une même portée reliée possiblement à une transmission verticale. Deux chiots Fox hound d’une même portée nés d’une mère séropositive à Leishmania ont été présentés après un contrôle sérologique positif. Une infection à Leishmania infantum a été détectée par …

Repression Of Proinflammatory Gene Expression By Lipid Extract Of Nostoc Commune Var Sphaeroides Kützing, A Blue-Green Alga, Via Inhibition Of Nuclear Factor-Κb In Raw 264.7 Macrophages, Young-Ki Park, Heather E. Rasmussen, Sarah J. Ehlers, Kara R. Blobaum, Fan Lu, Vicki L. Schlegel, Timothy P. Carr, Ji-Young Lee

Department of Food Science and Technology: Faculty Publications

We investigated whether lipid extract from a blue-green alga, N. commune, modulates proinflammatory gene expression in RAW 264.7 macrophages. The cells were incubated with N. commune lipid extract (0–100 μg/mL) and subsequently activated by LPS (100 ng/mL). Quantitative real-time PCR analysis showed that mRNA abundance of proinflammatory mediators, including TNF-α, COX-2, IL-1β, IL-6, and iNOS, was significantly reduced by N. commune lipid extract in a dose-dependent manner. Secretion of TNF-α and IL-1β into cell culture medium was also significantly decreased by N. commune lipid extract. Thin-layer chromatography-densitometry analysis showed that N. commune …

Modeling Residence Time Distribution In A Twin-Screw Extruder As A Series Of Ideal Steady-State Flow Reactors, Ajay Kumar, Girish M. Ganjyal, David D. Jones, Milford Hanna

Department of Food Science and Technology: Faculty Publications

Knowledge about and control of residence time distribution (RTD) is critical for determining optimal conditions in an extrusion process. In this paper, previously proposed models for RTD have been summarized and compared with the experimental data. The best-fit model was found to be a plug flow in series with a finite number of constantly stirred tank reactors having dead volume fractions. Parameters of the best-fit model were predicted from input variables (moisture content, screw speed, nozzle diameter and barrel temperature). Predicted RTD from the input variables had a r ²> 0.96. Experiments were conducted using a full factorial design with …

Comparison Of Amylose Determination Methods And The Development Of A Dual Wavelength Iodine Binding Technique, Thianming Zhu, David S. Jackson, Randy L. Wehling, Bhima Geera

Department of Food Science and Technology: Faculty Publications

It has long been recognized that limitations exist in the analytical methodology for amylose determination. This study was conducted to evaluate various amylose determination methods. Purified amylose and amylopectin fractions were obtained from com, rice, wheat, and potato and then mixed in proportion to make 10, 20, 30, 50, and 80% amylose content starch samples for each source. These samples, considered amylose standards, were analyzed using differential scanning calorimetry (DSC), high-performance size-exclusion chromatography (HPSEC), and iodine binding procedures to generate standard curves for each of the methods. A single DSC standard equation for cereal starches was developed. The standard curve …

Genotypic Characterization And Prevalence Of Virulence Factors Among Canadian Escherichia Coli O157:H7 Strains, Kim Ziebell, Marina Steele, Yongxiang Zhang, Andrew K. Benson, Eduardo N. Taboada, Chad Laing, Scott Mcewen, Bruce Ciebin, Roger Johnson, Victor Gannon

Department of Food Science and Technology: Faculty Publications

In this study, the association between genotypic and selected phenotypic characteristics was examined in a collection of Canadian Escherichia coli O157:H7 strains isolated from humans and cattle in the provinces of Alberta, Ontario, Saskatchewan, and Quebec. In a subset of 69 strains selected on the basis of specific phage types (PTs), a strong correlation between the lineage-specific polymorphism assay (LSPA6) genotype and PT was observed with all strains of PTs 4, 14, 21, 31, 33, and 87 belonging to the LSPA6 lineage I (LSPA6-LI) genotype, while those of PTs 23, 45, 67, and 74 belonged to LSPA6 lineage II (LSPA6-LII) …

The L-Type Calcium Ion Channel Cch1 Affects Ascospore Discharge And Mycelial Growth In The Filamentous Fungus Gibberella Zeae (Anamorph Fusarium Graminearum), Heather E. Hallen-Adams, Frances Trail

Department of Food Science and Technology: Faculty Publications

Cch1, a putative voltage-gated calcium ion channel, was investigated for its role in ascus development in Gibberella zeae. Gene replacement mutants of CCH1 were generated and found to have asci which did not forcibly discharge spores, although morphologically ascus and ascospore development in the majority of asci appeared normal. Additionally, mycelial growth was significantly slower, and sexual development was slightly delayed in the mutant; mutant mycelia showed a distinctive fluffy morphology, and no cirrhi were produced. Wheat infected with Δcch1 mutants developed symptoms comparable to wheat infected with the wild type; however, the mutants showed a reduced ability …

Allergenicity Assessment Of Genetically Modified Crops—What Makes Sense?, Richard E. Goodman, Stefan Vieths, Hugh A. Sampson, David Hill, Motohiro Ebisawa, Ronald Van Ree

Department of Food Science and Technology: Faculty Publications

GM crops have great potential to improve food quality, increase harvest yields and decrease dependency on certain chemical pesticides. Before entering the market their safety needs to be scrutinized. This includes a detailed analysis of allergenic risks, as the safety of allergic consumers has high priority. However, not all tests currently being applied to assessing allergenicity have a sound scientific basis. Recent events with transgenic crops reveal the fallacy of applying such tests to GM crops.

Functional Analysis Of The Fructooligosaccharide Utilization Operon In Lactobacillus Paracasei 1195, Yong Jun Goh, Jong-Hwa Lee, Robert W. Hutkins

Department of Food Science and Technology: Faculty Publications

The fosABCDXE operon encodes components of a putative fructose/mannose phosphoenolpyruvate-dependent phosphotransferase system (PTS) and a β- fructosidase precursor (FosE) that are involved in the fructooligosaccharide (FOS) utilization pathway of Lactobacillus paracasei 1195. The presence of an N-terminal signal peptide sequence and a LPQAG cell wall anchor motif at the C-terminal region of the deduced FosE precursor amino acid sequence predicted that the enzyme is cell wall-associated, indicating that FOS may be hydrolyzed extracellularly. In this study, cell fractionation experiments demonstrated that the FOS hydrolysis activity was contained exclusively in the cell wall extract of L. paracasei previously grown on FOS. …

Crop Rotation And Soil Amendment Alters Sorghum Grain Quality, Nanga Mady Kaye, Stephen C. Mason, David S. Jackson, Tom D. Galusha

Department of Food Science and Technology: Faculty Publications

Soybean [Glycine max (L.) Merr.] rotation enhances grain sorghum [Sorghum bicolor (L.) Moench] yield, but infl uence on grain quality has not been measured. The objective was to determine the effect of cropping sequence (CS) and soil amendment (SA) on grain yield and quality. Sorghum grain yield and quality, soil NO₃–N and water were measured in a rotation study in 2003 and 2004 on a Sharpsburg silty clay loam (fine, smectitic, mesic Typic Argiudoll). Cropping sequences were continuous sorghum, and sorghum rotated with non-nodulating and nodulating soybean. Soil amendments consisted of no amendment, manure (17–26 Mg …

Extraction And Characterization Of Starch From Alkaline Cooked Corn Masa, Wajira Srinanda Ratnayake, Andrew B. Wassinger, David S. Jackson

Department of Food Science and Technology: Faculty Publications

Starch granules undergo structural and morphological changes during food processing unit operations as they interact with other food ingredients. This study was conducted to isolate and characterize starch granules from corn masa. A proteolytic enzyme, thermolysin, was effective in separating and isolating starch granules from endosperm proteins present in masa. The efficiency of starch extraction using thermolysin was 74% (w/w), and subsequent analyses showed that the isolated granules were free of contaminants. Starch samples were characterized using light microscopy, SEM, DSC, and XRD. Starch granules isolated from masa had undergone internal structural changes and some granules (≈40%) lost birefringence during …

Corroborative Study On Maize Quality, Dry-Milling And Wet-Milling Properties Of Selected Maize Hybrids, Kyung-Min Lee, Timothy J. Herrman, Lloyd Rooney, David S. Jackson, Jane Lingenfelser, Kent D. Rausch, John Mckinney, Chris Iiams, Linda Byrum, Charles R. Hurburgh Jr., Lawrence A. Johnson, Steven R. Fox

Department of Food Science and Technology: Faculty Publications

A corroborative study was conducted on the maize quality properties of test weight, pycnometer density, tangential abrasive dehulling device (TADD), time-to-grind on the Stenvert hardness tester (SHT), 100-kernel weight, kernel size distribution, and proximate composition as well as maize dry- and wet-millability by six participating laboratories. Suggested operating procedures were given to compare their measurements and provide the variance structure within and between laboratories and hybrids. Partial correlation coefficient among maize quality properties varied among laboratories. The repeatability and reproducibility precision values were acceptably low for the physical quality tests, except for TADD and SHT time-to-grind measurements. The yields of …

Identification Of Escherichia Coli O157:H7 Genomic Regions Conserved In Strains With A Genotype Associated With Human Infection, Marina Steele, Kim Ziebell, Yongxiang Zhang, Andrew K. Benson, Paulina Konczy, Roger Johnson, Victor Gannon

Department of Food Science and Technology: Faculty Publications

Beta-glucuronidase-negative, sorbitol-nonfermenting isolates of Shiga toxin-producing Escherichia coli O157 comprise part of a clone complex of related enterohemorrhagic E. coli isolates. High-resolution genotyping shows that the O157 populations have diverged into two different lineages that appear to have different ecologies. To identify genomic regions unique to the most common human-associated genotype, suppression subtractive hybridization was used to identify DNA sequences present in two clinical strains representing the human lineage I O157:H7 strains but absent from two bovine-derived lineage II strains. PCR assays were then used to test for the presence of these regions in 10 lineage I strains and 20 …

Lupine Allergy: Not Simply Cross-Reactivity With Peanut Or Soy, Kim A. B. M. Peeters, Julie A. Nordlee, André H. Penninks, Lingyun Chen, Richard E. Goodman, Carla A. F. M. Bruijnzeel-Koomen, Sue L. Hefle, Steve L. Taylor, André C. Knulst

Department of Food Science and Technology: Faculty Publications

Background: Reports of lupine allergy are increasing as its use in food products increases. Lupine allergy might be the consequence of cross-reactivity after sensitization to peanut or other legumes or de novo sensitization. Lupine allergens have not been completely characterized.

Objectives: We sought to identify allergens associated with lupine allergy, evaluate potential cross-reactivity with peanut, and determine eliciting doses (EDs) for lupine allergy by using double-blind, placebo-controlled food challenges.

Methods: Six patients with a history of allergic reactions to lupine flour were evaluated by using skin prick tests, CAP tests, and double-blind, placebo-controlled food challenges. Three of …

Genome Evolution In Major Escherichia Coli O157:H7 Lineages, Yongxiang Zhang, Chad Laing, Marina Steele, Kim Ziebell, Roger Johnson, Andrew K. Benson, Eduardo Taboada, Victor Gannon

Department of Food Science and Technology: Faculty Publications

Background: Genetic analysis of Escherichia coli O157:H7 strains has shown divergence into two distinct lineages, lineages I and II, that appear to have distinct ecological characteristics, with lineage I strains more commonly associated with human disease. In this study, microarray-based comparative genomic hybridization (CGH) was used to identify genomic differences among 31 E. coli O157:H7 strains that belong to various phage types (PTs) and different lineage-specific polymorphism assay (LSPA) types.
Results: A total of 4,084 out of 6,057 ORFs were detected in all E. coli O157:H7 strains and 1,751 were variably present or absent. Based on this data, E. coli …

Gene Family Encoding The Major Toxins Of Lethal Amanita Mushrooms, Heather E. Hallen-Adams, Hong Luo, John S. Scott-Craig, Jonathan D. Walton

Department of Food Science and Technology: Faculty Publications

Amatoxins, the lethal constituents of poisonous mushrooms in the genus Amanita, are bicyclic octapeptides. Two genes in A. bisporigera,AMA1 and PHA1, directly encode ∝-amanitin, an amatoxin, and the related bicyclic heptapeptide phallacidin, a phallotoxin, indicating that these compounds are synthesized on ribosomes and not by nonribosomal peptide synthetases. ∝-Amanitin and phallacidin are synthesized as proproteins of 35 and 34 amino acids, respectively, from which they are predicted to be cleaved by a prolyl oligopeptidase. AMA1 and PHA1 are present in other toxic species of Amanita section Phalloidae but are absent from nontoxic species in other sections. The …

Classification Of Dry-Milled Maize Grit Yield Groups Using Quadratic Discriminant Analysis And Decision Tree Algorithm, Kyung-Min Lee, Timothy J. Herrman, Scott R. Bean, David S. Jackson, Jane Lingenfelser

Department of Food Science and Technology: Faculty Publications

A genetically and environmentally diverse collection of maize (Zea maize L.) samples was evaluated for physical properties and grit yield to help develop a standard set of criteria to identify grain best suited for drymilling. Application of principal component analysis (PCA) reduced a set of approximately 500 samples collected from six states to 154 maize hybrids. Selected maize hybrids were placed into seven groups according to their dry-milled grit yields. Regression analysis explained only 50% of the variability in dry-milling grit yield. Patterns of differences in the physical properties for the seven grit yield groups implied that the seven …

Serum Testing Of Genetically Modified Soybeans With Special Emphasis On Potential Allergenicity Of The Heterologous Protein Cp4 Epsps, Michael Hoff, Dae-Yeul Son, Michaela Gubesch, Kangmo Ahn, Sang-Il Lee, Stefan Vieths, Richard E. Goodman, Barbara K. Ballmer-Weber, Gary A. Bannon

Department of Food Science and Technology: Faculty Publications

Roundup Ready soy contains the CP4-enolpyruvylshikimate-3-phosphate synthase (CP4 EPSPS) protein. Serum IgE from two distinct populations of soy-allergic patients were recruited to determine their IgE-binding specificity. One population consisted of 10 adult patients from Europe, whose primary diagnosis was soy food allergy with some also having mite allergy. In addition, 6 primarily mite-allergic, 6 food-allergic (celery, carrot, milk, shrimp, walnut, and apple), and 5 non-allergic patients were tested. Another population consisted of 13 children from Korea, whose primary diagnosis was atopic dermatitis and secondarily soy and egg sensitization. In addition, 11 non-allergic patients were tested. Each patient population was extensively …

Genomic Deletion Marking An Emerging Subclone Of Francisella Tularensis Subsp. Holarctica In France And The Iberian Peninsula, M. P. Dempsey, M. Dobson, C. Zhang, M. Zhang, C. Lion, C. B. Gutiérrez-Martín, P. C. Iwen, P. D. Fey, M. E. Olson, D. Niemeyer, S. Francesconi, R. Crawford, M. Stanley, J. Rhodes, D. M. Wagner, A. J. Vogler, D. Birdsell, P. Keim, A. Johansson, S. H. Hinrichs, A. K. Benson

Department of Food Science and Technology: Faculty Publications

Francisella tularensis subsp. holarctica is widely disseminated in North America and the boreal and temperate regions of the Eurasian continent. Comparative genomic analyses identified a 1.59-kb genomic deletion specific to F. tularensis subsp. holarctica isolates from Spain and France. Phylogenetic analysis of strains carrying this deletion by multiple-locus variable-number tandem repeat analysis showed that the strains comprise a highly related set of genotypes, implying that these strains were recently introduced or recently emerged by clonal expansion in France and the Iberian Peninsula.

Identification Of A Putative Operon Involved In Fructooligosaccharide Utilization By Lactobacillus Paracasei, Yong Jun Goh, Andrew K. Benson, Vicki Schlegel, Jong-Hwa Lee, Robert W. Hutkins

Department of Food Science and Technology: Faculty Publications

The growth and activity of some Lactobacillus and Bifidobacterium strains are stimulated by the presence of nondigestible fructooligosaccharides (FOS), which are selectively fermented by specific intestinal bacteria. Consumption of FOS, therefore, enriches for those bacteria that possess metabolic pathways necessary for FOS metabolism. In this study, a DNA microarray consisting of 7,680 random genomic library fragments of Lactobacillus paracasei 1195 was used to examine genes involved in the utilization of FOS in this organism. Differential expression profiles between cells grown on FOS and those grown on glucose provided a basis for identifying genes specifically induced by FOS. Several of the …

Prebiotic Galactooligosaccharides Reduce Adherence Of Enteropathogenic Escherichia Coli To Tissue Culture Cells, Kari Schoaf, George L. Mulvey, Glen D. Armstrong, Robert W. Hutkins

Department of Food Science and Technology: Faculty Publications

Prebiotic oligosaccharides are thought to provide beneficial effects in the gastrointestinal tract of humans and animals by stimulating growth of selected members of the intestinal microflora. Another means by which prebiotic oligosaccharides may confer health benefits is via their antiadhesive activity. Specifically, these oligosaccharides may directly inhibit infections by enteric pathogens due to their ability to act as structural mimics of the pathogen binding sites that coat the surface of gastrointestinal epithelial cells. In this study, the ability of commercial prebiotics to inhibit attachment of microcolony-forming enteropathogenic Escherichia coli (EPEC) was investigated. The adherence of EPEC strain E2348/69 on HEp-2 …